The speed of TOF-MS with time array detection (TAD) developed can provide for the first time, adequate spectral generation rates with enough sensitivity to serve as a detector for comprehensive two-dimensional chromatography (2D GC); a technique where the second column axis may be as short as 4 8 seconds. To gain sufficient data along this axis for chromatographic reconstruction, generation rates in excess of 50 spectra/sec must be used. One objective is to develop a screening analysis for the presence of tetrachloro-dioxins. These analyses are now being run on expensive high-resolution mass spectrometers with a cost per sample in excess of $1400. A rapid screening method is being sought that will check for the presence of these compounds. Since in the experience of the CDC, 75 80% of the samples are negative for the presence of dioxins, this project should result in a cost savings as well as greater throughput. The second objective is to develop a screening procedure for complex mixtures of both persistent and non-persistent pesticides. The 2D data field created by the two different columns will be used to simplify the qualitative and quantitative analyses as well as greatly enhance the throughput. Only TOFMS has the speed to perform this task.